The invention relates to the concept of making it possible for any pumper/tanker truck with standard NFPA 1901 equipment to draft water from a location remote from a water bulkhead by making a suction hose connection to a streetside fire connection, thereby avoiding the need to locate the truck at the bulkhead. The purpose is to provide an unlimited water supply with capacity, reliability and convenience at least the equal of a water main/fire hydrant system at a greatly reduced cost.
There are numerous residential, commercial and industrial communities located along the coastal areas, for example, the Gulf of Mexico, in which the real estate has been created by dredging and bulkheading. In general, such properties consist of peninsulas and other land forms bordered by dredged canals along which means have been provided to protect the banks from erosion and to provide adequate depth at waterline for easy access to barges, boats and ships. It is usual that streets are located along the center of the peninsula on the opposite side of individual properties from the canal or other water surface.
For peninsular property in particular, it is very difficult and extremely expensive t provide a properly looped potable water system, which maintains proper protection of health standards for potable water and, at the same time, provide adequate firefighting water at standard hydrants. The initial installation of water mains and fire hydrants that comply with firefighting standards and with standards for potable water systems is frequently, therefore, either neglected or substandard, and retroactive installation or expansion of existing systems is exceptionally expensive.
The usual approach to obtaining firefighting water in these circumstances is to use pumper/tanker trucks to draft water directly from the canals or other adjacent water source. Depending on how close the truck can get to a bulkhead, the truck can be attached with one ore more lengths of suction hose with a strainer to the suction intake of the hose, drop the strainer end of the hose into the water, and begin pumping, provided the pumper has sufficient lift capacity and the strainer is designed to prevent clogging of the pump. In many coastal regions, e.g., along the coast of the Gulf of Mexico tidal variations are minimal with low tide seldom being more than two feet below mean high tide. Thus, the water-to-pump intake vertical separation near the bulkhead is seldom more than seven to eight feet. Connecting the truck directly to the water source works well, then, unless rains have rendered the bulkheaded property impassable and until such time as properties are developed to the point where access is limited by structures, fences, etc. Under these latter conditions, firefighting water will not be available by direct draft without excessive pumping distance and commensurate increase in the time required to initiate firefighting operations.
The purpose of the present invention is to avoid any problem relating to the accessibility of the tidal, lake or river water intended to supply the firefighting system. This is done by locating interconnecting risers at both the street and bulkhead to which standard NFPA 1901 suction hose connection using standard suction hose lengths are made which provide a continuous fluid path from the water to the street. Accessibility is then assured from a streetside connection as normally employed in water main/fire hydrant systems, regardless of those factors which would affect direct drafting from a truck located at the bulkhead.
In most residential areas adjacent to a body of water, the bulkheaded property grade level is 6 to 8 feet above mean high tide, and street elevations are comparable. In coastal areas which are subject to tropical storms, residences are predominantly built to comply with laws or regulations governing their construction; i.e., the living areas are built 12 to 16 feet above mean high tide and are, therefore, buttressed or built on columns. Typically only part of the ground floor is enclosed such that at least part of the underside of the main floor is exposed. Because of the high cost of this "manufactured" real estate, parcels of land are small and residences are built close together, e.g., with a 10 feet separation being frequent. Because of the elevated main floor, the construction tends to be predominantly frame. A community built of such structures creates an ideal situation for the rapid inducement and spreading of fires from structure to structure. Adequate fire protection, thus, requires an abundant source of water, fast application of the water to the fire and a high degree of reliability of water delivery to the fire.
Commercial and industrial activities located at waterside are similarly protected from storm tides and waves by construction at elevated heights. Light structures may be set on columns as is common for residences, but warehouses and factories may be set on an elevated grade such that air to feed the fire is more restricted. However, dockside warehouse and factory fires in such activities involve large buildings with a great deal of open space among the contacts such that fires are difficult to control once started, and they require a multiplicity of hydrants and trucks for adequate fire control. The present invention makes it possible and economical to provide for (1) as many sources of water as may be predictably required, (2) with sources located with maximum flexibility, and (3) each capable of supplying water to the maximum capacity of the pumpers. Where an elevated grade results in a need to exceed the lift capacity of an NFPA 1901 standard pumper truck, which is 25 feet, variations in the present invention may be necessary, but are readily apparent. For example, longer suction hoses than those normally carried by the pumper truck can be permanently connected at the waterside location which can be dropped into the water when needed. Alternately, pumps can be permanently installed which direct the water to the streetside or other location of the riser placed for truck connection.
In the many waterside communities and activities for which the present invention is suited, the supply of firefighting water is limited only by the number of pumper/tanker trucks that can be brought to the scene and connected to the natural water source. The reliability of the delivery of that water to a fire is a function of the lift and pumping capacity of the truck(s) at the scene, the availability of trained personnel, and one section of suction hose per truck which is equipped with a strainer at one end. However, any certified pumper/tanker truck has both the lift and pumping capacity to implement the water delivery system of the present invention in the vast majority of waterside communities, and strainers are standard on the required drafting hose carried on pumpers.
With respect to the initial use of the present invention, training is not a problem since the risers associated with the water delivery system of the present invention emulate a standard fire hydrant. Further, both the equipment and procedures associated with the present invention are NFPA 1901 standard. The connection of the water delivery system of the present invention to a pump truck is identical to the connection of a pump truck to a standard fire hydrant, therefore comprising a very simple system for dependable water delivery.
Factors to be considered are (1) the vertical distance from the pump truck intake to the water level, (2) the horizontal distance between the waterside and streetside risers, and (3) the need to lower the suction intake to at least 18 inches below the water surface to prevent cavitation. However, unless grade level has been raised well above that normally employed, especially in residential communities, vertical distance is not a problem for NFPA 1901 standard pumper trucks. Horizontal distance is not a problem in narrow peninsular communities, but for other dockside activities a practical limit of about 250 feet might be imposed unless a second pumper is available as a booster or larger diameter hose is used. Obtaining approximately 18 inches submersion of the suction intake is rarely a problem since bulkheads are designed to provide for boat, barge, etc. access at waterside.
Thus, compliance with applicable regulates can be assured for successful use of the present invention. Effective, reliable, affordable fire protection, the flexibility of location of the truck intake risers, the NFPA 1901 standard features and the economy of the system thus qualify the present invention as an acceptable alternative to water mains and fire hydrants for applications as described herein. Additionally, the unlimited water supply and the ease and economy of installing as many units as the situation may demand, even retroactively, means that redundancy of sources and fire trucks may be used to increase the level of protection to that demanded by the situation, including the increase of the number of firefighting units that can concurrently fight a fire such that pump failure can be eliminated as a significant factor affecting reliability.
For the applications described, effective and reliable fire protection demands both the previously emphasized compatibility with NFPA 1901 standard firefighting equipment and absolute immunity from fouling of the system. Physical fouling is prevented by the strainer on the suction hose intake. By isolating the connection from the waterside riser to the natural water source until the time of a fire, marine or aquatic biological fouling is avoided which previously has resulted in the failure of in-place drafting systems. Water left in the system for the purpose of minimizing the time required to begin pumping is fresh, potable, chlorinated water and is isolated from oxygen and sunlight so that fouling from biological growth is eliminated; this can be further enhanced by the addition of inexpensive chemicals such as bleach if chlorinated water is not available.
The present invention addresses features not previously addressed. These features include the ability to back flush the the water delivery system in an attempt to remove strainer blockage from the water side hard suction hose and the face that all NFPA approved fire trucks will carry these hard suction hoses as standard equipment. Firemen being knowledgeable in the use of said hard suction hose, will have no difficulty using this invention.
In addition to providing unlimited firefighting water, it does so at greatly reduced cost as compared with standard water mains and fire hydrants and, further, permits installation at any time; i.e., it can be installed when construction in the community has progressed to the point that it is needed. The ease with which a community can retrofit the installation of the water delivery system of the present invention avoids the time and ultimate monetary cost associated with the installation of standard mains and hydrants. The minimum cost saving is approximately ten to one when comparing the water delivery system of the present invention with presently prescribed looped mains and hydrants. Further, any level of reliability can be provided by increasing the number of fire pumper trucks or the density of installations. Since each unit of the water delivery system of the present invention is totally independent of the other units and independent of the potable water supply, there is not practical limit to the density of units within a community--other than the amount of money the community wishes to commit to fire protection. This feasible redundancy of units can offer great increases in reliability proportional to the number of pumper/tanker trucks available, and it is especially important in this regard when a multiplicity of trucks are required to control a massive fire since there is no effect of one truck on the supply of water to the others.
In a massive fire situation, a serious water supply problem may exist with respect to standard pressurized water main/fire hydrant systems. The water pressure associated with the potable water system is not effected by the use of this invention, thereby eliminating the potential drop in water pressure due to the demand for water in fighting one or more fires. The use of the present invention adds to the safety of the potable water system since there is no involvement of the potable water system, thereby eliminating the risk of contamination due to fire fighting use. Further, since the invention does not involve the potable water system, there is no consumption of vital, and possible scarce, potable water for use in firefighting.
One skilled in the state of the art will recognize that the unique results described have been achieved without the discovery of new physical principles. Rather, the water delivery system of the present invention is based on proven principles, but for which practical systems for their implementation have not previously been devised. Prior systems have failed to prevent inoperability as a result of marine or aquatic fouling; they failed to consider the requirement for strainers to preclude the clogging of the system or fouling of pumping equipment; they failed to provide for universal usage by all NFPA 1901 equipment; and they failed to comply with state and local laws or regulations pertaining to fire protection and the insurability or insurance rates applicable to such firefighting water supplies.
The essence of this system is truly revolutionary. There are no moving parts to present any mechanical problems thus adding to the simplicity of this invention. The system is maintained entirely by the application of a silicone lubricant on the metal parts. Should the system develop a major leak sufficient to interrupt the suction column, simply back flush the system and start again.
In certain prior references, such as U.S. Pat. No. 4,140,146 which issued Feb. 20, 1979 to E. E. Slanker, elaborate measures are taken to avoid the use of salt water in a fire fighting water delivery system and use primarily fresh water. Unlike the Slanker device, the present invention uses a very small amount of fresh water left in the system in standby condition, and then uses either fresh or salt water for fire fighting depending on availability. Protection rom salt water during fire fighting is considered unnecessary since the application of salt water to a fire in the type of construction described herein, would not cause any increase in damage over that which would be caused by the application of fresh water; the damage caused by fire, smoke and water (fresh or salt) would render inconsequential any additional damage that might be caused by the application of salt water.